Determination of Twelve Major and Minor Elements in Tourmaline by X-ray Fluorescence Spectrometry with Fusion Sample Preparation

Tourmaline is a class of boron-bearing aluminosilicate minerals. It has a complex chemical component and stable chemical property, and is difficult to decompose by wet methods. The high content of B₂O₃ makes it difficult to simultaneously determine major and minor elements in tourmaline. X-ray Fluorescence Spectrometry (XRF) was applied to determine Na₂O, MgO, Al₂O₃, SiO₂, P₂O₅, K₂O, CaO, TiO₂, V₂O₅, Cr₂O, MnO, TFe₂O₃ in tourmaline samples with fusion sample preparation in this study. The dilution ratio of 1:10 was set for the sample to flux lithium tetraborate-lithium metaborate-lithium fluoride (quality ratio of 4.5:1:0.4) in order to eliminate the particle size effect and mineral effect. When the tourmaline reference materials were unavailable, soil, stream sediment and different types of rock reference materials were used to establish calibration curves. The accuracy of the method was verified using reference materials that have chemical compositions similar to tourmaline. The relative standard deviation (RSD, n=11) was less than 4.2%. The proposed method was used to determine four different tourmaline samples, the results were in good agreement with the values obtained by wet chemical methods. This method solved the problem that tourmaline is difficult to decompose and eliminated the interference effect of boron. The analytical results are accurate and reliable. Compared with other methods, this method is easy to operate and has a short analytical time.